河北文安5．1级地震前后重力场动态变化  

Dynamic Gravity Changes before and after the 2006 Wen′an M5.1 Earthquake,Hebei Province

作　　者：王武星[1,2] 石耀霖[1] 张晶[2] 史彦华[3] 

机构地区：[1]中国科学院研究生院计算地球动力学重点实验室,北京100049 [2]中国地震局地震预测研究所,北京100036 [3]河北省地震局保定测量队,河北保定071000

出　　处：《地震》2009年第2期40-47,共8页Earthquake

基　　金：地震预测研究所基本科研业务专项(0207690226);国家科技支撑计划(2006BAC01B02-02)

摘　　要：分析了2006年7月4日文安5.1级地震前后文霸流动重力测网的观测结果,讨论了垂直形变和浅层地下水位变化引起的重力改变,并对重力资料进行了高程改正。研究结果认为,文安地震前后,测网出现了明显的异常变化,测区的重力异常以重力上升为主,且上升幅度大的区域主要在测网南部;地震震中在震前形成重力高梯度带,2005年10月至2006年4月短期内的重力变化表现最为明显;测区内的正负重力变化的分界线,地震前后出现逐渐偏转的特点,且在2007年10月逐渐恢复。In order to explore the abnormal gravity variations before and after the Wen＇an MS. 1 earthquake occurred on July 4 2006, the data observed by Wenba gravity observation network before and after the earthquake are analyzed. The relations between gravity change with vertical displacement and shallow groundwater level were discussed, and ele- vation effects are corrected. The results show that there were abnormal gravity changes before the MS. 1 earthquake, which appeared as gravity rising in the whole observation network especially in the south part of it. High gradient of gravity variation appeared around the epicenter before the MS. 1 earthquake, especially during the short period from October 2005 to April 2006. The boundary between the positive and negative gravity variations was gradually deflected and began recovering from October 2007.

关 键 词：文安地震 文霸测网 重力变化 

分 类 号：P315.7[天文地球—地震学]